Five people have died, 31 are hospitalised and eight remain unaccounted for following the eruption on Whakaari/White Island on Monday afternoon.

Watch the video above

Prime Minister Scott Morrison said 24 Australians were caught up in the devastation, and it's feared Australians make up as many as three of the five confirmed fatalities.

He says a further 13 Australians are currently hospitalised, while eight have been unaccounted for.

At a press conference on Tuesday morning, New Zealand Prime Minister Jacinda Ardern said people from New Zealand, Australia, the United Kingdom, the United States, China and Malaysia were among those on site.

In the video below: Several still missing after New Zealand volcanic eruption

A New Zealand volcano erupted suddenly on Monday, killing several and injuring dozens. Police say they don't expect to find any more survivors.

A New Zealand volcano erupted suddenly on Monday, killing several and injuring dozens. Police say they don't expect to find any more survivors.

"To our Australian family, we will do everything we can to support you as you have supported us," Ardern said.

Waikato Police Superintendent Bruce Bird said the death toll may rise.

"The pilot that went out there has provided a good indication that nobody else has survived the explosion."

Australians involved (information as at Tuesday morning):

24 in total

3 believed deceased

13 hospitalised

8 unaccounted for

Several people rescued from the area around White Island on Monday remain in a critical condition in hospitals around North Island with severe burns.

Anthony and Kristine Langford of Sydney are unaccounted for, according to the New Zealand Red Cross. Credit: Facebook

Many of these are believed to be holidaying Australians aboard the Ovation of the Seas cruise ship, which was on a day tour to the volcanic island.

Morrison said on Monday 24 Australians were caught up in the devastation.

"I have spoken several times this evening with New Zealand Prime Minister Jacinda Ardern and there is still no comprehensive or confirmed information about the well-being of those were impacted by the volcano eruption on Whakaari/White Island earlier today, including 24 Australians who were visiting the island as part of a cruise ship tour group.

Phone call no parent wants

Royal Caribbean called to ask Barbara Barham if she'd heard from her daughter before she'd heard of the devastation in New Zealand.

Her son-in-law's mother then called her to relay a voicemail left by the honeymooning 36 year old.

Newlyweds Lauren and Matt Urey. Credit: Facebook

It said he was "burned very bad" and was struggling to make phone calls because the reception was so bad.

"His hands were so badly burned it was hard for him to make a phone call."

Neither set of parents have heard from the couple since.

'Worse news to come'

In a press conference on Tuesday morning, Morrison said up to three Australians were among the dead.

"This is a very, very hard day for a lot of Australian families whose loved ones have been caught up in this terrible, terrible tragedy," Morrison said.

"But I fear there is worse news to come over the course of perhaps today or over the next few days."

Still holding out hope

The brother of Anthony Langford, who is missing with his wife Kristine and their teenage children, Jesse, 19, and Winona, 17, told 7NEWS he and the rest of the family are hoping their relatives found their way off the volcano and are recovering in hospital somewhere.

Rodney Langford said the family just doesn't "know anything at all".

"But I'm hoping that somebody knows anything, has seen my brother, knows my brother or has seen his wife or their kids."

Royal Caribbean, the cruise company operating the Ovation of the Seas, says Australians concerned about relatives travelling aboard the ship can call 1300 026 240